18x24x1 AC and Furnace Air Filter by Aerostar - MERV 8, Box of 6

Nominal Size: 18 x 24 x 1, Actual Size: 17 3/8" x 23 3/8" x 3/4" Comparable to 3M Filtrete MPR 600 Clean Living Comparable to Honeywell Micro Defense Plus FPR 5 Fights lint, dust mites, mold spores, pollen, pet dander, and dust. Change frequency 60-90 days, Made in the USA.